Enantioselective preparation of 1,3-dithiane 1-oxides by asymmetric oxidation of 1,3-dithianes bearing a chiral auxiliary
Abstract
Oxidation of 1,3-dithianes bearing a chiral auxiliary derived from (+) or (–)-camphor or diacetone D-(+)-glucose by the Sharpless reagent [Ti(OPri)4–diethyl L-(+)- or D-(–)-tartrate-ButOOH] affords, with high stereoselectivity, the monosulfoxides in good to excellent yields. Removal of the chiral auxiliary by base-catalysed hydrolysis yields (R)- and (S)-1,3-dithiane 1-oxides in high yields.